Caption: Sunflower (Helianthus sp.). The flower head of this tall, annual plant can grow to 30 centimetres in diameter. The outer flowers (yellow) are the ray florets and are sterile. The inner flowers (brown) are the disc florets. These disc florets mature into fruit, which are commonly called seeds. The seeds can be eaten or compressed to produce oil that is used in cooking. Sunflowers grow in warm and temperate climates, and are native to the Americas.